1. Field of the Invention
The invention relates to a cutting insert for a cutting tool, a tool seat for such a cutting insert, and a cutting tool having such a cutting insert, in particular a boring tool.
2. Description of the Related Art
In the field of machining technology, it is known not to form the cutting lip of a tool in one piece with the tool, but rather to design it as a separate component in the form of a cutting tip, an indexable cutting tip or a cutting body as cutting insert. Such a cutting body is known, for example, from DD 157 314 A.
The cutting inserts are used in special tools and in tools for producing relatively large lot sizes. As soon as the cutting lips located on the cutting insert are worn, the cutting insert is removed from the tool and replaced by a new cutting insert. There are therefore no downtimes for the regrinding of the tool. In addition, such cutting inserts are especially suitable for cutting lips made of special materials, for example carbide, cermet or ceramic, and for cutting lips set with diamond or similar materials. The cutting inserts can be both coated and uncoated. Here, the cutting insert can be made of the usually costly cutting material that is difficult to produce, whereas the tool can otherwise be made of a more cost-effective material that is simpler to produce. It is therefore also possible by means of the cutting inserts to produce special tools having cutting lips matched very specifically to the respective application.
The advantage of cutting inserts having a plurality of cutting lips working independently of one another, which are normally designated as indexable cutting tips, lies in the multiple applicability of the insert. Here, the material utilization is especially good. With respect to the material quantity used for the production of the cutting insert body, the proportion taken up by the cutting lips in such a multi-lip cutting insert is especially high.
According to the prior art, in order to fix the cutting body, a tool seat designed to be complementary to the geometry of the cutting body is provided on the tool. It is known, for example, from DD 148 314 A1 to fix a tetrahedral cutting insert in a tool seat by means of a pivotable clamping shoe. A disadvantage in this case is the large amount of space required by the clamping shoe. In addition, it is not possible to arrange an effective surface of the tool, for example a main or secondary cutting lip, in the region of the clamping shoe. An innately space-saving configuration of the tool seat is known from DE 1 140 045 B. A tetrahedral cutting body is again mounted there in a corresponding tool seat. A clamping element designed as a screw bolt serves for clamping the cutting body. The screw bolt is mounted such that it can be screwed back and forth in the tool by means of a screwing passage made in the tool. A disadvantage in this case is the weakening in the strength of the tool which inevitably accompanies the making of the screwing passage. In addition, the screwing passage and the screw bolt cannot be reduced in size in any desired manner in order to be able to still apply the requisite clamping forces via the screw bolt on the one hand and in order to be able to still usefully manipulate the screw bolt on the other hand. DE 24 55 612 A1 shows a similar design, which again requires a clamping element and a corresponding accommodating space for the clamping element on the tool in order to be able to clamp the cutting insert.
The object of the invention is to configure a cutting insert in such a way that it can be fitted in the tool in a simple manner and at the same time is easy to manipulate.